rtnl/ipv4: use netconf msg to advertise forwarding status

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index a4d75ea868ed638b0cf6c1bf689811aaa2268657..3dee071770d5dc091cee51d5c629d08db5050c22 100644 (file)
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -592,6 +592,8 @@ enum rtnetlink_groups {
 #define RTNLGRP_PHONET_ROUTE   RTNLGRP_PHONET_ROUTE
        RTNLGRP_DCB,
 #define RTNLGRP_DCB            RTNLGRP_DCB
+       RTNLGRP_IPV4_NETCONF,
+#define RTNLGRP_IPV4_NETCONF   RTNLGRP_IPV4_NETCONF
        RTNLGRP_IPV6_NETCONF,
 #define RTNLGRP_IPV6_NETCONF   RTNLGRP_IPV6_NETCONF
        __RTNLGRP_MAX

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 2a6abc163ed2fa9cc15d4be2f4e9e795ec9f08b5..020fdd2e6e1927bc972c378c1f81ed6c891eb76d 100644 (file)
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -55,6 +55,7 @@
 #include <linux/sysctl.h>
 #endif
 #include <linux/kmod.h>
+#include <linux/netconf.h>
 
 #include <net/arp.h>
 #include <net/ip.h>
@@ -1442,6 +1443,73 @@ static int inet_set_link_af(struct net_device *dev, const struct nlattr *nla)
        return 0;
 }
 
+static int inet_netconf_msgsize_devconf(int type)
+{
+       int size = NLMSG_ALIGN(sizeof(struct netconfmsg))
+                  + nla_total_size(4); /* NETCONFA_IFINDEX */
+
+       if (type == NETCONFA_FORWARDING)
+               size += nla_total_size(4);
+
+       return size;
+}
+
+static int inet_netconf_fill_devconf(struct sk_buff *skb, int ifindex,
+                                    struct ipv4_devconf *devconf, u32 portid,
+                                    u32 seq, int event, unsigned int flags,
+                                    int type)
+{
+       struct nlmsghdr  *nlh;
+       struct netconfmsg *ncm;
+
+       nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg),
+                       flags);
+       if (nlh == NULL)
+               return -EMSGSIZE;
+
+       ncm = nlmsg_data(nlh);
+       ncm->ncm_family = AF_INET;
+
+       if (nla_put_s32(skb, NETCONFA_IFINDEX, ifindex) < 0)
+               goto nla_put_failure;
+
+       if (type == NETCONFA_FORWARDING &&
+           nla_put_s32(skb, NETCONFA_FORWARDING,
+                       IPV4_DEVCONF(*devconf, FORWARDING)) < 0)
+               goto nla_put_failure;
+
+       return nlmsg_end(skb, nlh);
+
+nla_put_failure:
+       nlmsg_cancel(skb, nlh);
+       return -EMSGSIZE;
+}
+
+static void inet_netconf_notify_devconf(struct net *net, int type, int ifindex,
+                                       struct ipv4_devconf *devconf)
+{
+       struct sk_buff *skb;
+       int err = -ENOBUFS;
+
+       skb = nlmsg_new(inet_netconf_msgsize_devconf(type), GFP_ATOMIC);
+       if (skb == NULL)
+               goto errout;
+
+       err = inet_netconf_fill_devconf(skb, ifindex, devconf, 0, 0,
+                                       RTM_NEWNETCONF, 0, type);
+       if (err < 0) {
+               /* -EMSGSIZE implies BUG in inet_netconf_msgsize_devconf() */
+               WARN_ON(err == -EMSGSIZE);
+               kfree_skb(skb);
+               goto errout;
+       }
+       rtnl_notify(skb, net, 0, RTNLGRP_IPV4_NETCONF, NULL, GFP_ATOMIC);
+       return;
+errout:
+       if (err < 0)
+               rtnl_set_sk_err(net, RTNLGRP_IPV4_NETCONF, err);
+}
+
 #ifdef CONFIG_SYSCTL
 
 static void devinet_copy_dflt_conf(struct net *net, int i)
@@ -1467,6 +1535,12 @@ static void inet_forward_change(struct net *net)
 
        IPV4_DEVCONF_ALL(net, ACCEPT_REDIRECTS) = !on;
        IPV4_DEVCONF_DFLT(net, FORWARDING) = on;
+       inet_netconf_notify_devconf(net, NETCONFA_FORWARDING,
+                                   NETCONFA_IFINDEX_ALL,
+                                   net->ipv4.devconf_all);
+       inet_netconf_notify_devconf(net, NETCONFA_FORWARDING,
+                                   NETCONFA_IFINDEX_DEFAULT,
+                                   net->ipv4.devconf_dflt);
 
        for_each_netdev(net, dev) {
                struct in_device *in_dev;
@@ -1474,8 +1548,11 @@ static void inet_forward_change(struct net *net)
                        dev_disable_lro(dev);
                rcu_read_lock();
                in_dev = __in_dev_get_rcu(dev);
-               if (in_dev)
+               if (in_dev) {
                        IN_DEV_CONF_SET(in_dev, FORWARDING, on);
+                       inet_netconf_notify_devconf(net, NETCONFA_FORWARDING,
+                                                   dev->ifindex, &in_dev->cnf);
+               }
                rcu_read_unlock();
        }
 }
@@ -1527,15 +1604,23 @@ static int devinet_sysctl_forward(ctl_table *ctl, int write,
                        }
                        if (valp == &IPV4_DEVCONF_ALL(net, FORWARDING)) {
                                inet_forward_change(net);
-                       } else if (*valp) {
+                       } else {
                                struct ipv4_devconf *cnf = ctl->extra1;
                                struct in_device *idev =
                                        container_of(cnf, struct in_device, cnf);
-                               dev_disable_lro(idev->dev);
+                               if (*valp)
+                                       dev_disable_lro(idev->dev);
+                               inet_netconf_notify_devconf(net,
+                                                           NETCONFA_FORWARDING,
+                                                           idev->dev->ifindex,
+                                                           cnf);
                        }
                        rtnl_unlock();
                        rt_cache_flush(net);
-               }
+               } else
+                       inet_netconf_notify_devconf(net, NETCONFA_FORWARDING,
+                                                   NETCONFA_IFINDEX_DEFAULT,
+                                                   net->ipv4.devconf_dflt);
        }
 
        return ret;